ML18229A335

Relief Requests 60 and 61- Unit 3 Fourth 10-Year Inservice Inspection (ISI) Interval, Request for Relief from the American Society of Mechanical Engineers (ASME) Code - Half-Nozzle Repairs

ML18229A335
Person / Time
Site:	Palo Verde
Issue date:	08/17/2018
From:	Lacal M Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-07761-MLL/TNW
Download: ML18229A335 (13)

Text

10 CFR 50.55a MARIA L. LACAL Senior Vice President, Nuclear 102-07761-MLL/TNW Regulatory & Oversight August 17, 2018 Palo Verde Nuclear Generating Station P.O. Box 52034 U. S. Nuclear Regulatory Commission Phoenix, AZ 85072 ATTN: Document Control Desk Mail Station 7605 Washington, DC 20555-0001 Tel 623.393.6491

Subject:

Palo Verde Nuclear Generating Station Unit 3 Docket No. STN 50-530 Relief Requests 60 and 61- Unit 3 Fourth 10-Year Inservice Inspection (ISI) Interval, Request for Relief from the American Society of Mechanical Engineers (ASME) Code - Half-Nozzle Repairs Pursuant to 10 CFR 50.55a(z)(1), Arizona Public Service Company (APS) hereby requests Nuclear Regulatory Commission (NRC) approval to renew previously approved Relief Requests 52 and 54 that were alternatives to Section XI of the ASME Code (Code) that addressed the repair of a reactor vessel bottom-mounted instrument nozzle, and the repair of a pressure instrument nozzle on Reactor Coolant Pump 2A, respectively. Relief Requests (RRs) 52 and 54 were approved for the third 10-year ISI Interval, and this request is for the fourth 10-year ISI Interval. Proposed RR 60 is the replacement for the previously approved RR 52, and proposed RR 61 is the replacement to RR 54, which are provided as Enclosures 1 and 2 of this letter, respectively.

RRs 52 and 54 were submitted for the third 10-year ISI Interval [Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML14149A349 for RR 52 and ML15300A218 and ML16147A092 for RR 54] and requested an alternative pursuant to 10 CFR 50.55a(z)(1) to the 2001 edition / 2003 addenda of the ASME Code. APS is using the 2013 edition of the Code for the fourth 10-year ISI Interval. It has been verified that there have been no changes that impact the applicable Code requirements between the 2001 edition / 2003 addenda and 2013 Code edition.

The third 10-year ISI Interval for Unit 3 was initially scheduled to end on January 10, 2018. It has since been acknowledged that the third 10-year ISI Interval for Unit 3 was extended to May 31, 2018, as allowable by the ASME Code,Section XI, paragraph IWA-2430, in order to accommodate required examinations for the third interval during the refueling outage in the spring of 2018. This was described in RR 56 dated November 10, 2017 (ADAMS Accession No. ML17318A472), and approved by the NRC on March 9, 2018 (ADAMS Accession No. ML18067A073).

A response to this submittal is requested by January 10, 2019, as that is the latest date applicable to the third 10-year ISI Interval for Unit 3, if the full 12-month allowable extension of paragraph IWA-2430 of the ASME Code is applied. The fourth 10-year ISI Interval began on June 1, 2018, for Unit 3, as described in the NRC approval of RR 56 (ML18067A073). The delay in requesting relief prior to the start of the fourth 10-year ISI Interval has been entered into the site corrective action program. There is no operability or safety significance to this issue, as the underlying technical evaluations that supported the relief requests justified continued plant operation for 40 years.

A member of the STARS Alliance LLC Callaway

• Diablo Canyon

• Palo Verde

• Wolf Creek

102-07761-MLL/TNW ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Unit 3 Fourth 10-Year ISI Interval - Request for Relief - Half-Nozzle Repairs Page 2 No commitments are being made to the NRC by this letter.

Should you need further information regarding this relief request, please contact Matthew S. Cox, Licensing Section Leader, at (623) 393-5753.

Sincerely, Digitally signed by Lacal, Lacal, Maria Maria L(Z06149)

DN: cn=Lacal, Maria L(Z06149)

L(Z06149)

Date: 2018.08.17 15:50:00

-07'00' MLL/TNW/MDD/sma : Relief Request 60 - Request for Relief from the American Society of Mechanical Engineers (ASME) Code - Bottom-Mounted Instrument Nozzle : Relief Request 61 - Request for Relief from the American Society of Mechanical Engineers (ASME) Code - Reactor Coolant Pump 2A Pressure Instrument Nozzle cc: K. M. Kennedy NRC Region IV Regional Administrator M. D. Orenak NRC NRR Project Manager for PVNGS M. M. OBanion NRC NRR Project Manager C. A. Peabody NRC Senior Resident Inspector for PVNGS

Enclosure 1 Relief Request 60 Request for Relief from the American Society of Mechanical Engineers (ASME) Code Bottom-Mounted Instrument Nozzle

Enclosure 1 Relief Request 60 Request for Relief from the ASME Code Bottom-Mounted Instrument Nozzle Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station (PVNGS) - Unit 3 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)

Fourth 10-Year Inservice Inspection (ISI) Interval Request for Relief from the American Society of Mechanical Engineers (ASME) Code Bottom-Mounted Instrument Nozzle 1.0 Description During program updates for the fourth 10-year ISI Interval it was discovered that Relief Requests (RRs) 52 and 54 (specific alternatives for PVNGS Unit 3) had been previously submitted to the NRC, but only approved through the third 10-year ISI Interval. The third 10-year ISI Interval for Unit 3 began January 11, 2008, and may conclude no later than January 10, 2019, if the ASME Code-allowable extension of one year is applied to the 10-year interval (ASME Code,Section XI, paragraph IWA-2430)(Reference 1).

The ASME Code established third 10-year ISI Interval end date is January 10, 2018, for PVNGS Unit 3; however, in RR 56 (Reference 9), which was approved by the NRC staff (Reference 10), APS informed the NRC that a portion of the Code allowed one year extension period was going to be used for Unit 3 such that the third 10-year ISI Interval was scheduled to end May 31, 2018, to coordinate with the start of the combined 3-Unit Repair and Replacement Program and to permit final third interval examinations in the recent Unit 3 Spring outage.

Relief Requests 52 and 54 were submitted in accordance with 10 CFR 50.55a(z)(1) as alternatives to Section XI of the ASME Code and address the repair to a reactor vessel bottom-mounted instrument nozzle, and the repair to an instrument nozzle on Reactor Coolant Pump 2A, respectively. Relief for alternatives to the ASME Code were granted for both submissions. Specifically,Section XI, Article IWA-4000 regarding repair/replacement activities (RR 52 and 54), Article IWA-3000 regarding flaw characterization (RR 52), and Article IWB-2000 regarding subsequent examinations of repaired flaws (RR 52 and 54). The configuration of the approved repair has not changed and was evaluated for the remaining 40-year life of the plant. The NRC safety evaluations indicated that the relief requests expire at the end of the third 10-year ISI Interval. Relief will be needed for the alternatives to the ASME Code during the fourth 10-year ISI Interval.

The fourth 10-year ISI Interval began on June 1, 2018, for Unit 3, as described in the NRC approval of RR 56 (Reference 10). The delay in requesting relief prior to the start of the fourth 10-year ISI Interval has been entered into the site corrective action program. There is no operability or safety significance to this issue, as the underlying technical evaluations that supported RRs 52 and 54 justified continued plant operation for 40 years. Proposed RR 60 is the replacement for the previously approved RR 52, and proposed RR 61 is the replacement to RR 54. Approval of RR 60 is requested by January 10, 2019.

2.0 ASME Code Components Affected

The affected component is the reactor pressure vessel (RPV) bottom-mounted instrument (BMI) penetration number 3, which is an ASME Class 1, Examination Category B-P, Item B15.80 component as identified in Code Case N-722-1 (Reference 2).

1

Enclosure 1 Relief Request 60 Request for Relief from the ASME Code Bottom-Mounted Instrument Nozzle 3.0 Applicable Code Edition and Addenda The applicable ASME Code edition for the fourth 10-year ISI Interval for PVNGS Unit 3 is the 2013 edition.

The applicable construction ASME Code edition for PVNGS Unit 3 is the 1974 edition through the winter 1975 addenda.

4.0 Applicable Code Requirement The applicable Code requirements for which an alternative is requested are as follows:

Section XI, Article IWA-4000 provides requirements for repair/replacement activities.

IWA-4421 states, in part:

Defects shall be removed or mitigated in accordance with the following requirements IWA-4422.1(a) states, in part:

A defect is considered removed when it has been reduced to an acceptable size IWA-4422.1(b) states, in part:

Alternatively, the defect removal area and any remaining portion of the defect may be evaluated and the component accepted in accordance with the appropriate flaw evaluation provisions of Section XI Section XI, Article IWA-3000 provides standards for examination evaluation.

IWA-3100(a) states, in part:

Evaluation shall be made of flaws detected during an inservice examination as required by IWB-3000 for Class 1 pressure retaining components IWA-3300(b) states, in part:

Flaws shall be characterized in accordance with IWA-3310 through IWA-3390, as applicable.

Section XI, Article IWB-3000 provides acceptance standards for Class 1 components.

IWB-3420 states:

Each detected flaw or group of flaws shall be characterized by the rules of IWA-3300 to establish the dimensions of the flaws. These dimensions shall be used in conjunction with the acceptance standards of IWB-3500.

Section XI, Article IWB-2000 provides examination and inspection requirements for Class 1 components.

2

Enclosure 1 Relief Request 60 Request for Relief from the ASME Code Bottom-Mounted Instrument Nozzle IWB-2420(b) states, in part:

If a component is accepted for continued service in accordance with IWB-3132.3 or IWB-3142.4, the areas containing flaws or relevant conditions shall be reexamined during the next three inspection periods listed in the schedule of the inspection program of IWB-2400 5.0 Reason for Request During the preparation and review of ISI program documents for the fourth 10-year ISI Interval, it was determined that RR 52 had only been previously approved for the third interval. This submittal requests the use of the same identified alternative(s) for the fourth ISI Interval for Unit 3. Licensee RR 52 and supporting documentation was submitted in the following documents:

ADAMS Accession No. ML14149A349, as letter dated May 16, 2014 (Reference 3)

ADAMS Accession No. ML14141A545, as letter dated May 16, 2014 (Reference 4)

ADAMS Accession No. ML15023A047, as letter dated January 16, 2015 (Reference 5)

ADAMS Accession No. ML15023A039, as letter dated January 20, 2015 (Reference 6)

ADAMS Accession No. ML15037A048, as letter dated January 29, 2015 (Reference 7) 6.0 Proposed Alternative and Basis for Use Pursuant to 10 CFR 50.55a(z)(1), APS requests NRC approval of RR 60, which proposes an alternative to the ASME Code requirements of Section XI related to axial flaw indications identified in a Unit 3 reactor vessel BMI nozzle. Approval of this request was previously granted by the NRC for the half-nozzle repair and flaw evaluation as an alternative to the ASME Section XI requirements for flaw removal of IWA-4421, flaw characterization of IWA-3300, and successive examinations of IWB-2420. The NRC Safety Evaluation and letter of approval for RR 52 is available as ADAMS Accession No. ML15079A006 (Reference 8). The half-nozzle repairs performed on the Unit 3 reactor vessel BMI nozzle remain as previously repaired and evaluated. All physical plant parameters identified in the flaw evaluation and its supporting documentation remain valid and bounding. The half-nozzle repair and accompanying flaw evaluation have been analyzed for the licensed operating life of the plant and have previously been determined to provide an acceptable level of quality and safety.

Since the time that the BMI half-nozzle repair was implemented in refueling outage 3R17, in-core instrumentation nozzle 3 has been visually inspected in refueling outages 3R18 (April of 2015) and 3R19 (October of 2016). No indications or changes have been identified by the visual examinations post repair. Examinations will continue per the methods and frequencies described in Code Case N-722-1, which is required to be implemented per 10 CFR 50.55a. The unit heat-up and cooldown histories have been updated in plant documents consistent with the underlying corrosion analyses.

7.0 Duration of Proposed Alternative The duration for this request for approval of an alternative is for the fourth 10-year ISI Interval for PVNGS Unit 3 which will end on January 10, 2028.

3

Enclosure 1 Relief Request 60 Request for Relief from the ASME Code Bottom-Mounted Instrument Nozzle 8.0 Precedents South Texas Project Unit 1 - Request for Relief From ASME Section XI Requirements Associated with Characterizing Flaws in Bottom Mounted Instrument Penetration Welds (Relief Request RR-ENG-2-33), June 25, 2003, ADAMS Accession No. ML031780006 (Reference 11)

NRC letter dated September 29, 2004, Arkansas Nuclear One, Unit No. 1 - RE: Proposed Alternatives to Weld Repair and Examination Requirements for Repairs on Reactor Vessel Head Penetration Nozzles (TAC NO. MB9660), ADAMS Accession No. ML042890174 (Reference 12) 9.0 References

1. ASME B&PV Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components, 2013 Edition

2. ASME B&PV Code,Section XI Code Case N-722-1, Additional Examinations for PWR Pressure Retaining Welds in Class 1 Components Fabricated with Alloy 600/82/182 MaterialsSection XI, Division 1

3. APS Letter No. 102-06879, dated May 16, 2014, Palo Verde Nuclear Generating Station (PVNGS)

Unit 3 Docket No. 50-530, American Society of Mechanical Engineers (ASME) Code,Section XI, Request for Approval of an Alternative to Flaw Removal, Flaw Characterization and Successive Examinations - Relief Request 52, ADAMS Accession No. ML14149A349

4. APS Letter No. 102-06880, dated May 16, 2014, Palo Verde Nuclear Generating Station, Unit 3, Docket No. 50-530, Transmittal of Proprietary Documents for Relief Request 52, ADAMS Accession No. ML14141A545

5. APS Letter No. 102-06991, dated January 16, 2015, Palo Verde Nuclear Generating Station, Unit 3, Docket No. 50-530, Response to Request for Additional Information (RAI) for Unit 3 Bottom Mounted Instrument Relief Request 52 (Proprietary Version), ADAMS Accession No. ML15023A047

6. APS Letter No. 102-06992, dated January 20, 2015, Palo Verde Nuclear Generating Station, Unit 3, Docket No. 50-530, Response to Request for Additional Information (RAI) for Unit 3 Bottom Mounted Instrument Relief Request 52 (Non-Propriety Version), ADAMS Accession No. ML15023A039

7. APS Letter No. 102-07000, dated January 29, 2015, Palo Verde Nuclear Generating Station, Units 1, 2, and 3, Docket Nos. 50-528/529/530, Transmittal of Affidavit from AREVA for RAI Response to Relief Request 52, ADAMS Accession No. ML15037A048

8. NRC Letter dated March 30, 2015, Palo Verde Nuclear Generating Station, Unit 3 - Request for Approval of an Alternative to ASME Code,Section XI Requirements for Flaw Removal, Flaw Characterization, and Successive Examinations (TAC No. MF4169), ADAMS Accession No. ML15079A006

9. APS Letter No. 102-07604, dated November 10, 2017, Palo Verde Nuclear Generating Station Units 1, 2, and 3, Docket Nos. STN 50-528/529/530, Relief Request 56 - Unit 2 Third 10-Year Inservice Inspection (ISI) Interval Extension and Request to Adopt 2013 Edition of Section XI of the American Society of Mechanical Engineers (ASME) Code for the Fourth 10-Year Interval for Units 1, 2, and 3, ADAMS Accession No. ML17318A472 4

Enclosure 1 Relief Request 60 Request for Relief from the ASME Code Bottom-Mounted Instrument Nozzle

10. NRC Letter dated March 9, 2018, Palo Verde Nuclear Generating Station, Units 1, 2, and 3 -

Relief Request No. 56 to Extend Third 10-Year Inservice Inspection Interval for Unit 2, and to Adopt 2013 Edition of ASME Code,Section XI, for the Fourth 10-Year Interval for Units 1, 2, and 3 (EPID L-2017-LLR-0139), ADAMS Accession No. ML18067A073

11. STP Letter No. NOC-AE-03001550, dated June 25, 2003, South Texas Project, Unit 1, Docket No. 50-498, Request for Relief from ASME Section XI Requirements Associated with Characterizing Flaws in Bottom Mounted Instrument Penetration Welds (Relief Request RR-ENG-2-33), ADAMS Accession No. ML031780006

12. NRC Letter dated September 29, 2004, Arkansas Nuclear One, Unit No. 1 -

RE: Proposed Alternatives to Weld Repair and Examination Requirements for Repairs on Reactor Vessel Head Penetration Nozzles (TAC NO. MB9660) ADAMS Accession No. ML042890174 5

Enclosure 2 Relief Request 61 Request for Relief from the American Society of Mechanical Engineers (ASME) Code Reactor Coolant Pump 2A Pressure Instrument Nozzle

Enclosure 2 Relief Request 61 Request for Relief from the ASME Code Reactor Coolant Pump 2A Pressure Instrument Nozzle Arizona Public Service Company (APS)

Palo Verde Nuclear Generating Station (PVNGS) - Unit 3 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)

Fourth 10-Year Inservice Inspection (ISI) Interval Request for Relief from the American Society of Mechanical Engineers (ASME) Code Reactor Coolant Pump 2A Pressure Instrument Nozzle 1.0 Description During program updates for the fourth 10-year ISI Interval it was discovered that Relief Requests (RRs) 52 and 54 (specific alternatives for PVNGS Unit 3) had been previously submitted to the NRC, but only approved through the third 10-year ISI Interval. The third 10-year ISI Interval for Unit 3 began January 11, 2008, and may conclude no later than January 10, 2019, if the ASME Code-allowable extension of one year is applied to the 10-year interval (ASME Code,Section XI, paragraph IWA-2430)(Reference 1).

The ASME Code established third 10-year ISI Interval end date is January 10, 2018, for PVNGS Unit 3; however, in RR 56 (Reference 6), which was approved by the NRC staff (Reference 7), APS informed the NRC that a portion of the Code allowed one year extension period was going to be used for Unit 3 such that the third 10-year ISI Interval was scheduled to end May 31, 2018, to coordinate with the start of the combined 3-Unit Repair and Replacement Program and to permit final third interval examinations in the recent Unit 3 Spring outage.

Relief Requests 52 and 54 were submitted in accordance with 10 CFR 50.55a(z)(1) as alternatives to Section XI of the ASME Code and address the repair to a reactor vessel bottom-mounted instrument nozzle, and the repair to an instrument nozzle on Reactor Coolant Pump 2A, respectively. Relief for alternatives to the ASME Code were granted for both submissions. Specifically,Section XI, Article IWA-4000 regarding repair/replacement activities (RR 52 and 54), Article IWA-3000 regarding flaw characterization (RR 52), and Article IWB-2000 regarding subsequent examinations of repaired flaws (RR 52 and 54). The configuration of the approved repair has not changed and was evaluated for the remaining 40 year life of the plant. The NRC safety evaluations indicated that the relief requests expire at the end of the third 10-year ISI Interval. Relief will be needed for the alternatives to the ASME Code during the fourth 10-year ISI Interval.

The fourth 10-year ISI Interval began on June 1, 2018, for Unit 3, as described in the NRC approval of RR 56 (Reference 7). The delay in requesting relief prior to the start of the fourth 10-year ISI Interval has been entered into the site corrective action program. There is no operability or safety significance to this issue, as the underlying technical evaluations that supported RRs 52 and 54 justified continued plant operation for 40 years. Proposed RR 60 is the replacement for the previously approved RR 52, and proposed RR 61 is the replacement to RR 54. Approval of RR 61 is requested by January 10, 2019.

2.0 ASME Code Components Affected

The affected component is the pressure instrument nozzle attached to the safe end of the suction side of reactor coolant pump (RCP) 2A, which is an ASME Class 1, Examination Category B-P, Item B15.205 component as identified in Code Case N-722-1 (Reference 2).

1

Enclosure 2 Relief Request 61 Request for Relief from the ASME Code Reactor Coolant Pump 2A Pressure Instrument Nozzle 3.0 Applicable Code Edition and Addenda The applicable ASME Code edition for the fourth 10-year ISI Interval for PVNGS Unit 3 is the 2013 edition.

The applicable construction Code edition for PVNGS Unit 3 is the 1974 edition through the winter 1975 addenda.

4.0 Applicable Code Requirement The applicable Code requirements for which an alternative is requested are as follows:

Section XI, Article IWA-4000 provides requirements for repair/replacement activities.

IWA-4421 states, in part:

Defects shall be removed or mitigated in accordance with the following requirements IWA-4422.1(a) states, in part:

A defect is considered removed when it has been reduced to an acceptable size IWA-4422.1(b) states, in part:

Alternatively, the defect removal area and any remaining portion of the defect may be evaluated and the component accepted in accordance with the appropriate flaw evaluation provisions of Section XI Section XI, Article IWB-2000 provides examination and inspection requirements for Class 1 components.

IWB-2420(b) states, in part:

If a component is accepted for continued service in accordance with IWB-3132.3 or IWB-3142.4, the areas containing flaws or relevant conditions shall be reexamined during the next three inspection periods listed in the schedule of the inspection program of IWB-2400 5.0 Reason for Request During the preparation and review of ISI program documents for the fourth 10-year Interval, it was determined that RR 54 had only been previously approved for the third interval. This submittal requests the use of the same identified alternative(s) for the fourth 10-year ISI Interval for PVNGS Unit 3. Licensee RR 54 and supporting documentation were submitted in the following documents:

ADAMS Accession No. ML15300A218, as letter dated October 22, 2015 (Reference 3)

ADAMS Accession No. ML16147A092, as letter dated May 20, 2016 (Reference 4) 2

Enclosure 2 Relief Request 61 Request for Relief from the ASME Code Reactor Coolant Pump 2A Pressure Instrument Nozzle 6.0 Proposed Alternative and Basis for Use Pursuant to 10 CFR 50.55a(z)(1), APS requests NRC approval of RR 61, which proposes an alternative to the ASME Code requirements of Section XI related to evidence of leakage identified in a Unit 3 RCP 2A suction side instrument nozzle. Approval of this request was previously granted by the NRC for the half-nozzle repair and flaw evaluation as an alternative to the ASME Section XI requirements for flaw removal of IWA-4421 and successive examinations of IWB-2420. The NRC Safety Evaluation and letter of approval for licensee RR 54 is available as ADAMS Accession No. ML16172A038 (Reference 5). The half-nozzle repairs performed on the Unit 3 RCP 2A instrument nozzle remain as previously repaired and evaluated. All physical plant parameters identified in the flaw evaluation and its supporting documentation remain valid and bounding. The half-nozzle repair and accompanying flaw evaluation have been analyzed for the licensed operating life of the plant and have previously been determined to provide an acceptable level of quality and safety.

Since the time that the half-nozzle repair was implemented in refueling outage 3R18, the 2A RCP instrument nozzle has been visually inspected in refueling outage 3R19 (October of 2016). No indications or changes have been identified by the visual examinations post repair. Examinations will continue per the methods and frequencies described in Code Case N-722-1, which is required to be implemented per 10 CFR 50.55a. The unit heat-up and cooldown histories have been updated in plant documents consistent with the underlying corrosion analyses.

7.0 Duration of Proposed Alternative The duration for this request for approval of an alternative is for the fourth 10-year ISI Interval for PVNGS Unit 3 which will end on January 10, 2028.

8.0 Precedents PVNGS Relief Request 31 (Reference 8) for small-bore hot leg nozzles for similar half-nozzle repairs provides a precedent for NRC approval of similar requests for Section XI alternatives.

9.0 References

1. ASME Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components, 2013 Edition

2. ASME Code,Section XI Code Case N-722-1, Additional Examinations for PWR Pressure Retaining Welds in Class 1 Components Fabricated with Alloy 600/82/182 MaterialsSection XI, Division 1

3. APS Letter No. 102-07125, dated October 22, 2015, Palo Verde Nuclear Generating Station (PVNGS) Unit 3 Docket No. 50-530, American Society of Mechanical Engineers (ASME) Code,Section XI, Request for Approval of an Alternative to Flaw Removal - Relief Request 54, ADAMS Accession No. ML15300A218

4. APS Letter No. 102-07263, dated May 20, 2016, Palo Verde Nuclear Generating Station, Unit 3, Docket No. 50-530, Response to Request for Additional Information Regarding Relief Request 54, Alternative to Flaw Removal, ADAMS Accession No. ML16147A092

5. NRC Letter dated June 23, 2016, Palo Verde Nuclear Generating Station, Unit 3 - Relief Request 54 to Approve an Alternative to Flaw Removal for Reactor Coolant Pump 2A Suction Pressure Instrument Nozzle (CAC No. MF6806), ADAMS Accession No. ML16172A038 3

Enclosure 2 Relief Request 61 Request for Relief from the ASME Code Reactor Coolant Pump 2A Pressure Instrument Nozzle

6. APS Letter No. 102-07604, dated November 10, 2017, Palo Verde Nuclear Generating Station Units 1, 2, and 3, Docket Nos. STN 50-528/529/530, Relief Request 56 - Unit 2 Third 10-Year Inservice Inspection (ISI) Interval Extension and Request to Adopt 2013 Edition of Section XI of the American Society of Mechanical Engineers (ASME) Code for the Fourth 10-Year Interval for Units 1, 2, and 3, ADAMS Accession No. ML17318A472

7. NRC Letter dated March 9, 2018, Palo Verde Nuclear Generating Station, Units 1, 2, and 3 -

Relief Request No. 56 to Extend Third 10-Year Inservice Inspection Interval for Unit 2, and to Adopt 2013 Edition of ASME Code,Section XI, for the Fourth 10-Year Interval for Units 1, 2, and 3 (EPID L-2017-LLR-0139), ADAMS Accession No. ML18067A073

8. APS Letter No. 102-05324 dated August 16, 2005, Palo Verde Nuclear Generating Station, Units 1, 2, 3, Docket No. 50-528/529/530, 10 CFR 50.55a(a)(3)(i) alternative Repair Request for Reactor Coolant System Hot Leg Alloy 600 Small-Bore Nozzles (Relief Request 31, Revision 1), ADAMS Accession No. ML052550368 4